What we're happy to have this
ratio here this morning.

That's where the masters were.

But there it Auburn University.

You know we're in the real world for
a few years credit program with hearing.

You're a Georgia Tech three

followed by a joint faculty position and
weapons in the area University of Utah.

You know you join your authority
where it's research just very

like a machine biomedical
Microsystems' integrated by sections

Microsystems fabrication is
currently the associate editor for

Michael machine in the United States
with general electronics and

the associate other like machine for
the I can't believe transactions.

Today he's going to talk about biological
cells with micro And OK thank you.

He switches so it can turn out great.

OK so what I want to do today is I'm going
to give me a kind of energy action to

Microsystems and how they're used for

Biomedical biological analysis and
then give you a few examples

of systems that we worked on in our
laboratory that kind of fit that mold.

So it included background
would talk about.

The Magna forensic separation for
blood cells and ways

of using that technology for separating
white blood cells or red blood cells and

then go into separation of
breast cancer cells from blood.

And then kind of a downstream
technology from that which is N.P.N.

spectroscopy which is a.

A technique which can be used for
further analyzing cells.

And then we'll talk about some
neuronal interface Microsystems and

conclude at that point.

So many of you probably read
across the publications

that have motivation for developing these
microfluidic systems in general and

in the case of the bomb medical arena.

These are some of
the motivating factors for

developing these systems first of
all they allow you to develop these

minute try systems that have multiple
functions and are highly function.

Sophisticated as far as
a functionality goes and

they allow you to do analysis that
you previously couldn't do without

large benchtop type instrumentation and
a lot of additional

manipulation of samples by clinicians or
by laboratory workers.

So the vision is to develop systems
that allow you to put a sample in one

into the system and get an answer out
of the other into the system in a micro

device format so it doesn't require a lot
of operator interfacing which introduces

errors into analysis and
also a lot of cost into the analysis and

it also reduces the size obviously and
the time associated with analysis.

So there's many different
scaling advantages this.

These are some of
the scaling advantages and

Microsystems including a lot
less sample that's necessary for

doing an analysis many times samples or
are rare and very low volume.

If you portability.

So it gives you the possibility of not
only developing portable systems but

also home use type systems.

And better fact there's some new products
coming out in the near future that are for

genetic analysis home based
genetic analysis systems that

will allow you to to check for
things like propensity for disease.

So the performance advantages really come
down to the ability to do these analysis

in parallel and to do them in much
shorter times than what you are seeing

with the macro scale more conventional
analysis systems and we'll see some

examples of how that time is decreased
as we go through the presentation.

So what to do these systems have
several common components to

include the components include things
like Margaret channels Michael pumps and

now so you can manipulate fluids and
running these Microsystems they also

include mechanical components in
detectors such as Let's go to Tech

there's an optical detection mechanisms
that are built into these systems.

And obviously we have to have a way
of packaging these systems so

packaging microfluidic systems and of
highly functional microfluidic systems is

of great interest to the community and
actually is a large task to perform

it's not trivial to interface these micro
scale systems with a macro scale world

you find that many groups envision
billing systems and they go through and

they build the micro system then I find it
very difficult to actually interface with

it to get the sample then to get detect
to detect areas within the system.

So this is an example this a generic
example of a bio analysis system platform.

And really what it's meant to do is
meant to convey the multifunction

characteristic of these systems.

You know if you want to get a develop
a system where you put a sample in and

get an answer out of the system some
output of the system in this case what

we're using is a blood sample that
goes in one side of the system and

it goes through a number
of functional compartments.

That in the end allow you to get a genetic
analysis out the back of the system so

in this particular example where
you're putting blood into the system

it has to go through some technique
of separating the blood so that you

just have a component of the blood that
you're interested in in the case of blood.

What do you think you'd be interested in
if you're doing a genetic analysis or

not a biologist but.

So you want you want the white blood cells
that's really what you want from a blood

sample because red blood cells don't
are they're not a new Clayton cell they

don't have a nucleus they
don't have D.N.A. within them.

So you're looking for
the B.B.C.'s from the blood sample and

if you know a little bit about blood you.

You know that they're
not the most abundant

in the bloodstream you know there may
be one out of every ten thousand or so

cells a white blood cells a rest om our
red blood cells and maybe exfoliated

cells as well but most most of the blood
is as far as the so content or

red blood cells so you have to have some
way of collecting white blood cells and so

that's a first step in the overall
process after you do that you have to go

through and
you have to somehow extract the D.N.A.

from the white blood cells that's what
this unit does it's called a solid days

extraction system so it extracts the
D.N.A. content from the white blood cells.

And then after that you have to go through
steps such as P.C.R. to amplify the D.N.A.

you don't have a lot of D.N.A. copies
coming from this extraction process.

So you have to amplify it so that your
signal is large enough to be detected in

a microsecond of Microsystems' So you go
through this P.C.R. process plumber eyes

Chain Reaction to the D.N.A.
and then after that you can do a D.N.A.

detection through a number
of different mechanisms but

really what this is meant to convey
again is that to do to create a.

For platform we have
sample in an answer out

here choirs multiple functions
built into the micro system.

The ability to mix and
to manipulate the fluids in a Microsystems

to get a number of fluids in
a number of electrical leads in and

out to call you need to
cool interfaces as well for

these for these Microsystems So
they're complex in their totality and

what we're not showing here is is
the interface the integration and

packaging that's necessary to
get you back to the macro scale.

So there's two different approaches that
people use is just like what you'd run

into in trying sort of occasion you
can make things monolithically or

you can make things in a hybrid
module type approach and

so the module approach requires that
you make each function or maybe one or

two functions on a chip.

He then put those on a common substrate
with other functional components.

They have to be electrically interface
they have to be optically as well as

fluid equally interface with one another.

So it's a little bit more
complex than Then let's say just

a let's go interface thing we know
the logical interface is not trivial but

this requires also the fluidic interfacing
is an optical type interfacing.

Could also use a monolithic approach
many of the monolithic systems are kind

of like what we had seen in the first
slide and that's the layer approaches

where you have embedded fluid channels and
better detectors in valves and

such that allow you to to perform these
functions not only at the surface of

these Microsystems' but also the inner
layers of these micro system so many of

these are made using are made using glass
materials and plastic materials and

the reason for that is because it's really
too full of the first reason is that

conventional analysis is done
on those type materials and so.

People that are doing these
analytical techniques

in laboratories around the world are
comfortable with materials like glass and

also a number of different
type of plastic materials.

So that's one reason why there's a strong
push environmental Microsystems' to work

on them and the glasses and
plastics arena.

But there's also the ability to optically
interface with those materials easily.

So you can get optical signals into the
inner layers of these materials get and

read optical signals out.

Many of the detectors that are used in
biomedical analysis are fluorescent or

at least optical based detection
technology so you need to be able to

interface with those
systems in optical fashion.

So this is again the overall concept so

what we're going to talk about today is
we're going to use at least in the first

part of the talk we're going to use this
is an example in talk about the first

parts of the system we're going to talk
about ways of taking a role sample in and

going through some of these personal
preparation techniques ways of

collecting white blood cells and
other rare cells from a blood sample and

ways of analyzing those using
impedance spectroscopy and so

we'll really concentrate right here and
then maybe spend a little bit of

time on the the electrophoresis sort of
the D.N.A. analysis section of it as well.

So this you have a system
that allows you to do

all of the functions that we had seen
in the schematic from the last slide

it doesn't go to Chip format so
we have cell separation.

Technologies and we have it separated
from another chip that contains

the saw the base extraction D.N.A.
amplification.

And the D.N.A.
analysis section of it but it's a.

Substrate based system has interfaces
that are made with on it as well.

So this is kind of your first look at some
of the technology or some of the approach

taken some approaches that can be used for
interfacing these systems interfaces

that are shown here are realized
in this slide and they

are still a part of fee based interfaces
so we can start a part of the system

over the building to build
the system to build these interfaces

up that allow us to interface our
capillaries for getting fluids in and

out of these Microsystems' they
allow us to create valves and

pumps pneumatically control valves and
pumps through these interfaces.

There's optical windows for
detection in these as well as the ability

to enter into integrate
integrated circuits and

electrical functionality into
these interfaces as well so

it gives us everything we need as
far as flexibility and ability to

interface with these different detection
mechanisms and integration needs.

So this is what the system looks
like it has a it's the same

system it just doesn't have all
the complexity of the packaging in it.

It has a cell separation component
has M.P.S. spectroscopy component.

You have to lie still.

Why blood cells before you can extract
the D.N.A. and amplify the D.N.A.

and analyze the D.N.A.
So really what amounts to.

And so
this is what I want to talk about is

a technique called Magneto precess and
what we used Magneto for

rhesus for what we're using it for
is a way of separating the red and

white blood cells and a raw blood sample
of blood is a very complex sample

if you look at it it's
contents it's probably.

Fifty percent solids and
so it's a very it's almost

almost a tissue in the complex of the.

So it's a lot of percent solids and
really what we're looking for

just this very small amount of the overall
content within the blood samples so

what we are showing here is
a principle called Magneto for

races that uses a magnetic field
as a way of creating forces

on the red blood cells in the white
blood cells because we know that

both of those cell types have
a certain magnetic susceptibility So

if we introduce a Bagnet force then we
can use that as a way of manipulating or

creating or
impinging a force on these cells.

So the way that we do that is creating a
magnetic field gradient we start with just

a magnetic field from a standard magnet or
a relatively high power magnet but

it's not electro magnet and
then creates a magnetic field that then

creates a gradient that's close to a micro
wire that we create in our micro system so

we use an external magnet we have a small
wire that we've defined magnet out of

magnetic material in a Microsystems and
that creates these gradients that then

produces the forces on the white
blood cells in the red blood cells.

We have to do that we can operate this and

there's one called the pair magnetic
mode in the other is a diabetic.

And since way the difference in those
is that we're in Taishan of the magnet

in the system so if we or in one
particular direction we get the pure

magnetic mode you know there's
a diamagnetic mode and I say actually what

that does is it creates kind of
the opposite force on the particle so

if the red blood cells were forced
toward the wire with a pair of magnetic

they'd be forced away from
the wire with a diamagnetic.

And so this is the way the system
works a pair of magnets but

I'm going to talk about the dive magnetic
mode because it's just a counter.

Part of it.

So you simply put magnets up against
the side of the Micro Channel that has

a fluid flowing through it.

And if we were lucky enough and
it would start flowing and

what happens is the red blood
cells in a pair of magnetic motor.

Are attracted to this rider that we've
defined in the center of our Michael Flynn

a channel.

So when they exit the exit out
the center number to exit our outlet

in the system of the white blood cells
are pushed away to the exit one and

exit three one and three from the system.

And so we're using this magnetic force
as a way of separating the blood cells.

As a comparison.

This is a macro device which does the
centrally the same same type operation.

So it's you know it's
about ten senators unlink

the capillary inside of it's around four
meters about three point six meters long.

The analysis is all about
the same time frame is our

Microsystems this is the micro system
it's a glass slide based format.

And so the sample is put in here.

It's separated as it travels down the
micro system is where the magnetic wire is

and it comes out of one two and three is
separated blood sample at the other round

and also takes about five minutes we get
better efficiency in the micro system

didn't they do in the macro system and we
doesn't really require near the complex of

the it's a glass based micro system it has
a standard magnet next to it and that's

all it takes is no external electronics
associate with this particular device.

It's very portable and
can be in vision use for

many applications that can take
advantage of that portability.

So this is examples of
the separation from the outlet so

this is the outer part of
the samples flow in this direction.

This is the wire that we defined in the
Micro Channel with the blood flowing down.

This shows what it looks like
without a magnetic flux I could run.

Video but it would look just like
that is pretty high margin isn't it.

And there's no separation really occurring
and this is with the magnetic field or

with the magnetic field applied
if you were in a video and

it is run quite like I want to run.

You see that most of the red blood
cells go in the center around and

not all of them in this particular
design we would lose probably twenty or

thirty percent of them to these Alan
one and out with three in this case.

So what we did was we tried dude.

Tried to decide how we would increase
the efficiency of the system and so

what we ended up doing is a cascade
basis to mostly that just a second.

But this shows before we get to that
that the efficiency of the separation is

proportional to the speed of the blood
this going through the system so

if you increase the speed you
decrease the efficiency and

it stands to reason that the magnetic
force has less time to react or

to act on the cells so there's less of a
chance of it pulling it into that center.

So it shows the separation for this

stage system around seventy percent for
collection of red blood cells.

We also did

the specifics on why blood cells
strange is not showing that appear

to projector seized up for
a minute for self.

But this this is well

doesn't like that slow and what I showed.

Which showed the white blood cell
separating and going out into alley one

and out with three
thinking it come back on

dare go back to this one I want it
again this is what I'm trying to show.

Let me show in this mode.

This is a cascade based system so
what happens is the blood comes in here

in the last system that you
saw just had one stage so

they had one wire that it was
attracted to in this case we have

multiple stages within the system so red
blood cells are attracted to this edge and

actually pull down into
the center channel.

Some of the remaining red blood
cells are pulled down here and

the very last remaining blood cells are
pulled out red blood cells are pulled down

here so it's kind of a way of.

Sweeping the red blood cells down into
the center channel and multiple stages.

And so by doing this I think we
can go back to slide show here.

And by doing this we were able to create
this system looks very similar to

the one that you had seen before but
it has multiple stages and so

we call it a cascade based system and
you can see that

in this cascade based system that the red
blood cells this is separation at

point three almost all the red blood
cells are in the center channel and it

turns out that almost all the white blood
cells on the outer channel the system.

So what the system allows us to do with
the ends it allows us to collect there

are cells that we're interested in for our
final analysis and show this to some of

their fish separation fish and see what's
around ninety percent and this system.

This is a video of the white
blood cells are going to try it.

And you can see that the white blood cells
they're there for us and the stain in

this case white blood cells are going out
into this island these are all red cells

that are flowing down the center and
the fish and see for the red light.

Why blood cells was around the same
patient the right around ninety eight

percent of patients here so
it also turns out that

you can use this technique for for
separating not only white blood cells but

other nucleated cells in this and
this magnify Reddick separation system so

this is a example an example of
separating exploded cancer cells and

you know I it's a sample that
we mix we made up ourselves but

essentially had a blood sample that we
introduced breast cancer cells into.

And we firstly stain the red breast
cancer cells and you can see that there

flowing down channels or outlets one and
three and so it gives us a way

of collecting other rare cells from
blood other than just white blood cells.

And so what we can do from that point is
after we've ran the blood sample through

the system we've collected the cells that
are of interest using the magnet for

it except ration we want to further
characterize those cells and

the way that we do that is through this
technique called impedance spectroscopy so

you can envision those cells that
are anally one in three being routed

to this in a way our way of
analysis cavities where so

is our position within the analysis
cavity that contains two electrodes

about most who have four electrodes for
doing in Pinas tomography but

essentially have cells that
are trapped in these cavities and

then we do an opinion spectrum
spectrograph of the cell itself.

So what we do is we're simply
measuring impedance Z.

value over a frequency range and so you
get a signature a certain impedance and

a magnitude of phase associated
with a particular type of cell.

And so this is what it looks like
is allowed to go model for that.

So we have electrodes on
either side you have a.

Well sitting in between the cell itself
is modeled is a parallel network.

So it has a membrane impedance
that has a side of Plasm

side of Plasm as well as the other
membrane on the other side a cell.

So this is a cell as plopped down
in the system in addition to that

of the electrodes aren't snuggly
against the cell you have

these electro polarisation of thanks.

If you also have to include due
to the nature of the solution.

So essentially this is the model of
electrical model for the system and so

it allows you to analyze things like the
membrane characteristics the electrical

touristic So the membrane and it turns
out that different cells have different

electrical characteristics and the
membranes in disease cells have different

electrical characteristics then the normal
cells of a particular type as well.

So you can use this is
a way of really analyzing

the physiology
electrophysiology of the cells.

So I'm going to go through a little
bit about how these devices are made.

We make these on silicon silicon process.

And these are the analysis cavities
that are built on to the silicon so

we go through a number of techniques that
you know you can vision the Poly and

type cavities if we want to use poly and
we have some cavities.

Where we've defined electrodes in of this
have this is a four electrode system but

the cell sits in the middle.

There's a tiny via at the bottom.

That's used to pneumatically kind of suck
the cell down into the analysis cavity and

also teams to project the cell out when
we don't want to do any other analysis

with it so that shows a very small two
micron view at the bottom is used for

capture So this is a silicon wafer
that has this type configuration.

We also have to put a interface on me.

So these are actually represent
fluid channels that flow over.

The radio microanalysis cavities
that connect to capillary tubing.

So this particular example is

really meant to show you
the sensitivity of this technique.

So what it allows you to do in this case
is take cells that are of the same time

and to start modifying arm are changing
the activity of the channels that allow

chemicals to go inside into and
out of the cells so these channels that

the sodium and potassium come in and
out of the cell and other

molecules in of the cell can be
manipulated through through chemical

intervention so if you take this is a crow
actually crime with and cells there

use their part there in that adrenaline
gland so they secrete adrenaline.

And so they if you if you add this

particular chemical to
a culture with colds and

cells it will block the potassium channel
so that TASM show no longer operates.

So you can imagine looking again at that
membrane model that let's go model for

a membrane.

If you have a channel that was reading

through its lead in charge
of molecules through.

And you've also been blocked that then
what's going to happen is this going to

be less leaky right as we have
more of a capacitive nature to it.

So now your impedance of that
membrane is changed somewhat.

It's changed from a leaky capacitor
to a less linking capacitor and

you pick that up and these again and

phase are magnitude in phase plots for
the impedance over a frequency range.

You know get a big change of magnitude but
you get a big change in impedance that's

associated with that phase change that
we're talking about of that capacitance

change becoming a more
capacitive membrane.

So even within the same cell type
it's all coming from inside.

If you modify the activity of
the channels in those cells

then you can pick that up using
spectroscopy so it can be used for

very sensitive soul analysis
where the cells are different.

They're just the activities
different from one cell to the next.

There's experimental
results in the last for

well no it's not one syllable I

don't know how many Well you know there's
the number of cells there obviously but

it's maybe for
one cell of each type in this case.

But we have a lot of data for
each each of these experiments and

you find that the data is
very very tight fitting and

we'll see that in some of the day that we
see in just a second for breast cancer.

So it turns out for breast cancer.

There's a number different stages of
breast cancer starting with normal.

Breast tissue and
it goes all the way through med and

static type cancer and
they're in this process.

So you know change in
the way they changes they

there's a lot of up regulation and
down the road regulation of products that

they're producing There's a lot of changes
in the membranes of the cells so they go

from just a normal membrane to they bled
membrane where they're much thicker.

So you can imagine if they become thicker
then we can pick that up using a passed

back process because we've changed
the membrane characteristics.

And so what we want to do is we want to
see if we can use impedance spectroscopy

to detect breast cancer
cells that have actually

each one of these stages of cancer from
normal through fully metastasized cells.

And so
this is an example of some of that data.

So this data is for

about twenty cells I think it shows
you that how close the data falls and

the difference in these cell types
are first of all normal cells normal.

So.

And these are early stage
breast cancer cells and

these are late stage breast cancer cells.

And they look different.

They look different on the microscope and
that's normally how these analysis

are done is they do install a G.
by taking a sample cutting it across

a sheet looking on the microscope staining
it and deciding visually whether or

not they have cancer and that sample.

And so this gives you more and
more quantitative way of doing

that by again analyzing single cells and
looking at their response.

So using these different cell types we
did the impedance spectrum a spectrum for

them from around forty Hertz and this was
up to three megahertz and you can see

that there is a distinct difference in the
cell types based on what stage of cancer.

You know one cancer that they're in so
it gives you a way of distinguishing so

all types as well as
distinguishing activity

of a given cell questions.

OK what I'm

going to do is give you permission
to do this which slide shows

and I want to pick out talking a little

bit about Microsystems for
interfacing with neurons.

So we're leaving the blood
sample arena and so

manipulation and collection and
those analysis collection and

other systems and
going to neuronal based analysis systems.

This particular system is really
interesting because when it allows you to

do is it allows you to to grow your
Rons in this micro system on a format

that has a little lead for stimulation and
recording it also has this micro

system our microfluidic system component
that allows you to culture in each.

One of these wells individually.

So these are wells that
have their own environment.

But the most interesting thing
about it is that isolates

fluid environments to these different
wells and allows the neurons to grow

wherever they want they can grow
freely throughout the micro system so

cells that originate in one chamber can
grow into the next chamber and vice versa.

Whereas the fluids can't.

Can mix there's barriers fluid barriers
that prevent that from happening.

So what allows you to do is allows you
to do experiments on the you know the so

many and then the distal end of neurons
that have been cultured in these systems

you can look at the facts
of different drugs and

different toxins on those different
regions of the cell and so we work with

groups at Emory that are interested
in studying things like Parkinson's

disease and understanding the basis for it
and it's a newer degenerative disease and

that's really what the system is good at
is is analyzing what happens at different

portions of the cells by isolating
them chemically from one another.

So this is a two chamber system.

It's a micrograph of a two tamer system.

This is a pity a mass based
microfluidic system so

it's going on the base with
all the electrodes and

such pattern and then the fluid chambers
are here and here and the structure

itself is made up a mass of fluid barrier
is around each one of these wells.

You can see a whole lot here with this.

Is this we were using do you or
do you explain it.

So this is taking away some neural neural
tissue from the spine popping it into one

of these compartments and letting it
grow and we saw in these systems.

We had the ability to start neurons
in one chamber and this shows

them growing into another change you see
the neural tracks in these other chambers.

Not only growing to the adjacent chamber
but also grew in a pattern way so

we can take the neurons and their acts
on star growing and we can pattern

different chemicals on the surface
that align those axons into different

tracks and so we can get tracks of axons
down the other in the other compartment.

So not only is it for fluid isolation and
culturing but it gives you the ability to

really direction lies
the growth of these neurons.

So it shows a little bit more that we
use in this case we use college and

as a molecule for direction lies in
the neural growth pattern college and

on the surface and then after doing
that the neurons would prefer to go

on the collagen and and
you can convince them to do that.

And show some of the closer a picture of
a Explain how the has the extensions going

from it these are the electrodes
are used for stimulating and

recording and
you can't really see it very well but

there's no Ron's going throughout that
environment and we had to face that

system with a commercially available
multichannel systems micro Let's root

a recording apparatus so this connects
back to a large computer that has.

You know has all the software and

such for stimulating recording for
manipulating the data once you get it.

So it's nice to have that
infrastructure already there and

you just plop your research device
into that into that set up so

we've made our lead our pin lead outs and
such so

that they they fit this jig that was
part of the Emmy recording system.

So this is a kind of a two D.

system right when we talk about is
really two D. electrode system.

This is a three D.
version of the same thing.

It fits into the N.B.A. system just like
the last one did has the same pan out.

But now we have a three D.
environment in this and.

The center of this culture.

So we have neurons which grow
throughout this three D.

environment more of a natural fashion.

Neural rays are great but
they're not three D.

And so there's a lot of scientists that
would prefer to do their experiments and

three D. because it more mimics
what you find naturally.

So in this system.

It's all micro machine then there's
ways of these are all so there's

fluid that comes in from the backside it's
released the ports on the front side.

There's also electrodes would go

over two tabs which then allow them to
go vertically up onto these tower rays.

So these tell razor fluid to be functional
they're logically functional for

stimulating recording.

This is one of the shows
optical monograph of them

that shows what they look
like you can see the leaves.

Coming up the length of them and
going to different points.

There's also fluid channels.

This is another view of it using
a scanning electron micrograph.

So one of the big things you have to worry
about whenever you're working with any

biomedical or biological
material is by compatibility and

by compatibility varies what that means
varies from application application

in the case of the broad analysis system
we were trying to culture cells in

that environment were simply
trying to analyze the cells and so

the body compatibility issues are much
different than they are in a system where

you're trying to grow cells and so
by compatibility is a moving target.

And there's no blanket statement
about compatibility that fits for

all applications but in this case
we were trying to work with and

she right materials and
we found that they were not very by

compatible actually they were highly
toxic for these neurons and these neurons

are very very sensitive they're
probably some of the more sensitive.

There are so
that you try to culture and so

this is one of the really acid tests for
compatibility.

It took us years it probably
took us three years.

A large group of people working
on this that knew a lot.

Well by compatibility it wasn't me is the
leave that area but we had people on board

that were experts in this area and so what
we ended up doing is we ended up using

this protocol for by compatibility for
this issue eight material we tried many

many different things to use conventional
back compatibility treatments and

this is what we ended up doing
in the end the work force.

And so we see neurons growing here we did
a lot of fluorescent imaging to look at

a lot of dead ratios we compared them to

standards that were
cultured at the same time.

Show some more neurons
growing on the system.

This is a fluid borne
electrical leads here.

It's probably better pitches and this.

This is C M of the neurons growing on this

is as you went to our
fluid pour the logical.

Lead the neurons are going growing happily

throughout the material after
the back compatibility treatment.

What would happen if you didn't go through
the bio compatibility treatment was you

have absolutely nothing right on
the surface and in fact in the case of as

you weight materials the entire petri dish
at least within the perimeter of maybe.

Two centimeters would be dead
around the as you know a material.

So you really had to figure out how to
leach out those toxins from the material.

Again we did a lot of a lot of analysis a
lot of Did I say isn't this case the green

presently labelled cells or live the red
fluorescent least label cells are dead.

It's a nuclear nucleus
likeliness based staying for

the Terminator whether the nuclear tests
were intact or not in these cells.

So again we had these systems and
we had to create an interface form.

We use Pedia mess as an interface for.

From some of the fluid testing.

So we created molds and poor P.M.S.

material is kind of a flexible
plastic material and

we're able to create create packages
that we put the system into then and for

testing is the silicon based
system with a ring for

culturing in the system in the center and
that goes into this

apparatus that we have seen before with
the two D. system and so the cells

are culture here and the information
is sent back to the rest of the system

the electrodes you know there's a lot of
things you have to learn about when you're

talking about performing experiments
with more stimulation recording in

electro pores ation is an important
aspect you want to use materials that

electro materials that can easily
pick up the neural activity

the signals from the neurons are on
the micro ball to millivolt scale.

So you need them to use a material that's
capable of picking up those signals and

without going through all the letter
chemistry associated with that

one of the better materials
to use this platinum black.

So all the electrodes within the culture
were electroplated with platinum black

before we perform the neural culturing so
that when we stimulate a recorded

we were able to do that with this
polarisation and electrode material.

This is a set up once again that fit
into and and that's pretty much it.

I think I'll stop there
any question thank you

glad to answer any questions or by me yes.

I didn't go over that I have
a students working on that

think he's in there right now but you know
one of my students working on phrenic

there's a number of different ways of
doing it using free since in fact but

we're working on a technique
he's a director for he says for

performing a similar separation.

So you can use the positive and
negative forces produced on cells

as a way of attracting them from
electrodes and so yes you can do that and

use that technique for
cells operation your protein

is to use a magnet for example rater to
get rid of all the red blood cells and

to use the separator to further
classify the white blood cells

and other rare cells like cancer cells and
cancer cells.

So it's kind of we're using
a cascade cascade fashion and

downstream from that is N.P.R.
spectroscopy So

you know the particular system I'm talking
about first starts with a magnet for

an except ration then die letter for
an example and then appears spectroscopy

to completely analyze the cells and
then what you have there.

Yes.

Yeah it was assembled by hand by
a student that doesn't drink much coffee.

They come in very patiently No
actually they simply process after

the students you know I used to maybe
ten ten minutes for an entire array.

So it really was a very difficult for
me to take a long time yet.

The electrical leads the question is
how to get from a horizontal vertical.

Well we stand with all of you to define
the horizontal leads we also used

to define the vertical leads and
at the interface was we used a solder tab.

So we saw we had a low
melting temperature Sautter

that was low enough melting point that
we could melt it in the presence of so

we used a ten so
saw that melts at around two

hundred degrees C. we heat up the entire
structure about two hundred degrees C.

that solder in a connected reflow and

create our horizontal
interconnect that was also

able to do that we sometimes

use buffers sometimes we don't goes to
get away from buffers we like to use

we have systems.

We're working on systems for
plasma separation as well.

So we have systems that have shown so
separation but

we also have plasma and
platelets type separation systems.

There are a lot of applications for
those as well.

For

the experiments we've done
we've found that there's a lot

of consistency from sample to sample.

We don't see a lot of variation
from sample sample but

I can't say that either has the lead
because I don't know that that's

a good blanket statement to make and
we haven't done enough experiments to do.

Yes right

here.

You know the boat for we try to
use be consistent with our buffer.

So we always use the same buffer
same electrolytic solution has

the same resist him you know he
has the same characteristics.

So we try to use the same boat for
each time but

we also try to build our cavity so
there's a cell set snugly down in them so

that the buffer plays a minimal role so
that the M.P.'s

who are measuring is really the impedance
of the snow not the buffer.

So we really try to fabricate in that way

because it will add a lot of
variability to the to the analysis.

So there are tricks if you want to nice
tight fit to your data then you've got to

you've got to be looking at
the same thing every time.

And so that's one of one trick to do that
is to put everything in there so in this

kind of snow fashion then houses and
milliseconds.

Well second time frame.

You know what I would have said
you know what I've shown is

a lot of data over a wide range
of a large frequency range and

you don't need that much
data to do analysis

in the end you just need a few points and
so you can easily knock knock down

the time by decreasing the data
that you take in the system.

We don't go over maybe five megahertz or
so

because we have a lot of parasitics
that start popping up that cause

the signals to kind of drown together
most information we find below that.

But there is.

You know there's I think there's a lot
of interest in our potential for

that higher frequency range as well and

we thinking about that but we haven't
really moved in that direction very much

P.C.R. is pretty standard and I
Microsystems Now there's many people have

demonstrated that we have shown
here was an I.R. based P.C.R.

so P.C.R. involves heating and
cooling you do that.

Heating cooling cycle a number of
times to create that amplify D.N.A.

And so we're using I.R.
heating and I are heating and

those kind of diffusion based
cooling in the system and

they work fine where we can do P.C.R.
and LESSON two or

three minutes macrocell systems
That's our No two hours.

This is much much quicker and

yes it's pretty standard stance
all the fodder for you where you

define your device and you pour the P.M.S.
and then peel it up after it's cured.

It's pretty common.

Yes we do in our labs here.

Yes it's very easy to implement a lab.

It's kind of messy process but
it's easy to implement.